The instant invention relates to hypodermic control syringes, i.e. syringes for irrigation, injection and suction, and more particularly to such a syringe that can be used with one hand.
Normal syringes are used only to inject fluids whereas control syringes are used both for injection (irrigation) and removal (suction) of fluids in tissue. Often a physician or nurse has only one hand free with which to operate a control syringe, which means that only one hand is available to push the plunger down into the barrel for irrigation and for pulling the plunger up the barrel for suction.
Heretofore control syringes designed for one-hand operation have employed a thumb ring attached to the end of the plunger and two finger rings attached to the syringe barrel. In operation, the index and middle fingers were positioned within these two finger rings and the thumb in the thumb ring. These three-ringed syringes, however, have not proven satisfactory. One problem has been the difficulty in threading the index finger, the middle finger and the thumb through the three separate rings. Another problem has been a feeling of instability once the syringe is on the hand, because the rings are relatively thin and in most cases are much larger than the diameter of the fingers and thumb. Furthermore, because of the larger finger rings projecting from opposite sides of the barrel, the syringe must be nearly twice as wide as the package for a conventional syringe. The three-ringed syringe presents a manufacturing problem in that complicated molds are required to accommodate the unwieldy syringe structure.
Accordingly, the instant invention overcomes all of the foregoing problems by providing a control syringe which can be conveniently operated by one hand and a syringe barrel which can be manufactured using a single mold cavity and core pin, i.e. a two part mold, and apparatus for manufacturing such a syringe barrel.